Investigation of revised AS 4324.1 partial load factors for steel bulk materials handling structures

Abstract

The Australian Standard AS 4324.1-1995 titled, ‘Mobile equipment for continuous handling of bulk materials - General requirements for the design of steel structures’ has been revised (to be published in 2017). A key objective is to address inconsistencies in the current code associated with partial load factors for structural design, when compared with modern structural design standards; a single load factor for all load cases in a load combination is replaced with new partial load factors in the revision as per the modern Limit States Design (LSD) method. This study considers the nature of two existing steel structures: a 150t Radial Stacker and a 1500t Bucket-wheel Reclaimer, to validate the effects of the proposed changes to partial load factors on structural design compliance. Based on AS 4324.1, structural analyses were carried out on steel members of both structures to check compliance with AS 4100. Studies consist of five load combinations (I, II, III/6, III/8 and III/10). Results from two sets of partial load factors (the AS 4324.1-1995 vs 2017 load factors) show that, for the machines investigated and for all five load combinations, the 1995 and 2017 AS 4324.1 load factors produce similar LCRs with only minor differences. Therefore, cost implications for this change are expected to be minimal.